Boosting electron transport process over multiple channels induced by S-doped carbon and Fe7S8 NPs interface toward high-efficiency antibiotics removal.

Abstract

The enhancement of electron transport process on multiple channels of C-Fe and C-S-Fe bonds between dual-reaction centres was investigated for stimulating the antibiotics degradation in Fenton-like processes. Herein, multiple channels structure of sulfur-doped carbon coupled Fe7S8 cluster through C-Fe bond and C-S-Fe bond was constructed through density functional theory (DFT), and S-doped carbon framework coated Fe7S8 nanoparticles (Fe7S8/SC) Fenton-like catalyst was prepared through hydrothermal and subsequent sulfuration process. The DFT calculations revealed that electrons are thermodynamically transferred from carbon to iron along both C-Fe and C-S-Fe bonds. The optimized Fe7S8/SC catalyst exhibited desirable catalytic property for Fenton-like degradation for various antibiotics, the removal of amoxicillin, norfloxacin, and tetracycline hydrochloride reach 98.9%, 97.8%, and 99.3% respectively within 40min under neutral pH, and catalyst also demonstrated excellent cycle stability after five runs. The excellent degradation effect of antibiotics by Fenton-like catalyst was attributed to the intensified electron transport process by multiple electron transfer channels between dual reaction centres, making FeII easier to regenerate. This study spreads a new route for the enhancement of electron transport process in Fenton-like catalysts by constructing multiple channels.